First, kill all weeds. You must maintain the weed-free condition while groundcover is establishing. (I would kill a couple of times over a period of 6-8 weeks.) Since the area is quite large and mostly sunny, you could hydroseed with Lespedeza if a taller groundcover will work for you. You may need a different groundcover for the shady areas, depending on how much of that there is. I see only disadvantages to using the concrete block edging.

Request the answer to 2 questions before posting the method I use for this type of situation when possible.
1. Distance between rear of house and beginning of the red clay slope?
2. Is that a roadway at the top of the slope where I see three telephone poles?